How Does Temperature Change Along a Helical Path?

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the temperature at a point in space is T(x,y,z) = x^2+y^2+z^2

and there is a particle traveling along the helix given by

\sigma (t) =(cos(t),sin(t),t)

a) find T'(t)

T&#039;(t) = \frac{\partial T}{\partial x} \frac{dx}{dt} + \frac{\partial T}{\partial y}\frac{dy}{dt}<br /> + \frac{\partial T}{\partial z} \frac{dz}{dt}

= -2cos(t)sin(t) + 2sin(t)cos(t) +2t = 2t

b) find the temperature at time t = \frac{\pi}{2} + 0.01

= cos^2 (t) + sin^2 (t) + t^2

evaluated at the given t

\approx 3.50how does this look?

thanks!
 
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The last answer doesn't look right, I mean 1 + t^2, ##\pi^2 \over 4## should be about 2.5, not 3.5.
 
verty said:
The last answer doesn't look right, I mean 1 + t^2, ##\pi^2 \over 4## should be about 2.5, not 3.5.


1+\left( \frac{\pi}{2} + 0.01\right)^2 = 3.49891702681
 
jonroberts74 said:
the temperature at a point in space is T(x,y,z) = x^2+y^2+z^2

and there is a particle traveling along the helix given by

\sigma (t) =(cos(t),sin(t),t)

a) find T&#039;(t)

T&#039;(t) = \frac{\partial T}{\partial x} \frac{dx}{dt} + \frac{\partial T}{\partial y}\frac{dy}{dt}<br /> + \frac{\partial T}{\partial z} \frac{dz}{dt}

= -2cos(t)sin(t) + 2sin(t)cos(t) +2t = 2t

b) find the temperature at time t = \frac{\pi}{2} + 0.01

= cos^2 (t) + sin^2 (t) + t^2

evaluated at the given t

\approx 3.50


how does this look?

thanks!
It looks good !
 
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There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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